Place 4 ounces cream cheese in a food processor. Add wasabi, 2 teaspoons lemon juice, and salt to taste. Process until smooth. Transfer to a small bowl.
Place another 4 ounces cream cheese in a clean food processor. Add the salmon scraps and salmon roe to the food processor. Add 2 teaspoons of lemon juice, and process until smooth. Transfer to a small bowl, and set aside.
Process the remaining 8 ounces cream cheese with the remaining 3 1/2 teaspoons lemon juice in a clean food processor until lightly whipped.